Table 3.

Classification of pancreas allograft rejectiona

aAdapted from reference33.
IInflammation of undetermined significance, with septal mononuclear infiltrates and the absence of venous or acinar involvement
IIMinimal rejection, with septal inflammation and venous endotheliitis (lymphocytes attached to the endothelium, with damage and elevation of the endothelium from the basement membrane); in the absence of venous endotheliitis, at least three of the following features also define grade II rejection: (1) septal inflammatory infiltrates with a mixed lymphocyte appearance (large “activated” and small lymphocytes), (2) eosinophils, (3) acinar inflammation in up to two foci (a collection of at least 10 mononuclear cells), or (4) ductal inflammation
IIIMild rejection, with septal inflammation consisting of a mixed lymphocyte population and acinar inflammation in at least three foci and with eosinophils, venous endotheliitis, ductal inflammation, and acinar single-cell injury as a byproduct of sampling error; the latter is present as cellular apoptosis or necrosis
IVModerate rejection, with arterial endotheliitis and/or necrotizing vasculitis, usually with features of grade III rejection also
VSevere rejection, with extensive acinar lymphoid or mixed inflammatory infiltrates, with multicellular foci or confluent acinar necrosis